Ethylenically unsaturated olefins without heteroatom substitution typically have low copolymerization rates with polar monomers such as acrylates. The copolymerization technology of olefins with polar monomers is reviewed in WO 03/070783 and WO 2005/054305, both owned by PPG Industries Ohio, Inc. The olefins are described as electron donating type monomers and the acrylates are described as electron accepting monomers.
In WO 03/070783, Examples A and B of the copolymers they feed 3 or 4 different charges into a reaction vessel over several hours maintaining a temperature of 140-160° C. and pressures from 5 psi to 62 psi in Example A and 40 to 360 psi in Example B. Molecular weights were number averages of 2293 and 4274 while the weight averages were 8317 and 12,856 gram/mole. These copolymers were blended with more conventional latexes and made into curable film forming compositions.
In WO 2005/054305, Examples 1-4 were 25/20/55 w/w/w of isobutylene/hydroxypropyl acrylate/butyl acrylate polymerized into a copolymer by the method of the patent application. The monomers and di-t-amyl peroxide were prepared in three separate feed tanks and commingled in a feed line just prior to addition to the 5-gallon stirred reactor. The reactor was maintained between 200 and 210° C. and at a pressure of 500 psi for a residence time of 16 to 25 minutes, The resulting polymer was reported to have a composition of 21 wt. % isobutylene, 27 wt. % hydroxypropyl acrylate, and 52 wt. % butyl acrylate. The copolymer was reported to have number average molecular weights between 1446 and 1699 and weight average molecular weights between 2781 and 3441 g/mole.
U.S. Pat. No. 4,198,330 discloses the modification of polyurethane dispersions by polymerization of acrylic monomers in the presence of the waterborne polyurethane particle.
U.S. Pat. No. 3,705,164 teaches the use of acetone as a diluent in the prepolymer to prepare aromatic polyurethane dispersions free of NMP that are further modified with a polyacrylic polymer.
U.S. Pat. No. 5,662,966 teaches the preparation of aromatic polyurethanes that are NMP free using acetone in the prepolymer using dhnethyloi butanoic acid as a dispersing diol agent.
U.S. Pat. No. 5,637,639 discloses NMP free polyurethane compositions that use low amounts of acetone as a diluent in the prepolymer.
U.S. Pat. No. 4,655,030 discloses the preparation of aliphatic polyurethane-acrylic dispersions via a process that renders them free of NMP.
U.S. Pat. No. 5,137,961 discloses the preparation of surfactant free and solvent free polyurethane-acrylic dispersions.
U.S. Pat. No. 4,927,876 discloses the preparation of waterborne polyurethane and urethane acrylic compositions containing diphenyhnethane diisocyanate and using NMP as a diluent in the prepolymer.
U.S. Pat. No. 6,239,209 teaches the preparation of oxidatively curable aromatic polyurethane-acrylics using NMP as a diluent in the prepolymer.
WO 99/16805 discloses aqueous polymer dispersions containing a water-dispersed polyurethane polymer and a vinyl (preferably acrylic) polymer.
WO2006/002865 discloses NMP free aromatic polyurethane and urethane-acrylic compositions that use methyl ethyl ketone as a diluent in the prepolymer.